In the present study, we reported the isolation and molecular characterisation of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing endophyte and its effect on alleviating drought stress in maize. Ten morphologically distinct indigenous plant growth-promoting rhizobacteria (PGPR) from maize roots and rhizosphere were screened for multiple plant growth-promoting (PGP) traits, and of ten, two strains (DHK and B1N1) possessing maximum PGP traits were evaluated at three water stress regimes in maize: (i) 80% field capacity (FC), (ii) 60% FC, and (iii) 40% FC for 45 days, starting 15 days after sowing to the maturity. Inoculation of DHK strain with maize at 80% FC induced a significant increase in plant biomass (root biomass, 86.67%; shoot biomass, 111.63%) together with decreased reactive oxygen species and increased activity of antioxidant enzymes (superoxide dismutase, 14.11 U/g fresh weight; peroxidase, 1.14 U/g fresh weight and catalase; 14.91 U/g fresh weight) compared to uninoculated control at same water regime (80% FC). The derivative strain also significantly accrued nutrients in maize and enhanced total chlorophyll and amino acid content in comparison with non-inoculated plants. 16S rDNA analysis of DHK strain revealed its lineage to Bacillus subtilis. Present investigations demonstrated the potential of the bacterial partner in alleviating drought stress in maize.

在本研究中，我们报道了产生1-氨基环丙烷-1-羧酸（ACC）脱氨酶的内生菌的分离和分子特征及其对减轻玉米干旱胁迫的作用。从玉米根部和根际中筛选出十种形态独特的本土植物促生根际细菌（PGPR）的多种植物促生长（PGP）性状，在十种中，在三个水中评估了两个具有最大PGP性状的菌株（DHK和B1N1）玉米的胁迫方式：（i）80％田间生产能力（FC），（ii）60％FC和（iii）40％FC，持续45天，从播种到成熟后15天开始。用80％FC的玉米接种DHK株后，植物生物量显着增加（根系生物量为86.67％;枝条生物量为111。与未接种的对照组相比，活性氧含量降低了63％，同时活性氧含量降低，抗氧化酶的活性增加（超氧化物歧化酶，新鲜重量为14.11 U / g；过氧化物酶，新鲜重量和过氧化氢酶为1.14 U / g；新鲜重量为14.91 U / g），与未接种的对照相比水情（80％FC）。与未接种的植物相比，该衍生菌株还显着增加了玉米中的养分并提高了总叶绿素和氨基酸含量。DHK菌株的16S rDNA分析揭示了它的血统枯草芽孢杆菌。目前的研究表明细菌伴侣在缓解玉米干旱胁迫方面的潜力。